地质学家通过分析火山岩磁性特征，重新确定了中美洲与南美洲的主要碰撞时间1。研究发现这一关键的板块构造事件发生在距今约1000万年之前，比科学界此前的认识更早1。
研究团队以哥伦比亚中部Combia火山岩为研究对象，该火山岩形成于约1260万至600万年前1。研究人员采用磁性结构分析技术，通过检测岩石内磁矿物的方向变化来追踪地壳变形过程1。数据显示，到了晚中新世时期，与碰撞相关的地壳缩短和变形已大幅减弱1，这表明主要碰撞阶段发生得更早。研究由Victor Piedrahita和J. Li领导，获得中国国家自然科学基金的支持1，相关成果已发表于《地球与行星物理学》2026年第10卷第1期1。
A team of geologists led by Victor Piedrahita and J. Li has determined that the primary collision between Central and South America occurred approximately 10 million years ago, earlier than previously understood 1. The researchers analyzed magnetic properties of late Miocene volcanic rocks from the northern Andes in Colombia to reach this conclusion 1. By examining the orientation of magnetic minerals within rocks from the Combia volcanic formation—dated between approximately 12.6 million and 6 million years ago—the team identified when major crustal shortening and collision-related deformation significantly diminished 1.
The findings indicate that by the late Miocene epoch, the most intense phase of the Americas' collision had already substantially weakened 1. This research, supported by China's National Natural Science Foundation, was published in Earth and Planetary Physics, Volume 10, Issue 1, in 2026 1.
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